an EventHelix.com blog

LTE Downlink Frame Structure

This article will explain the downlink frame structure. For the beginners, there is always a confusion about the frame structure, the physical channels etc, so to make their job easy, I am writing this article.

To start with, what does the downlink frame structure consists of? The answer is simple, it contains the downlink channels and signals. Refer article LTE Physical Downlink Channels for more details. The LTE frame is nothing but a imaginary grid of time vs frequency , where there are placeholders for different channels and signals, for Eg: the dowlink control channels are always restricted to first 3 symbols or less, of the subframe. The frame structure changes depending on the cyclic prefix type, bandwidth and duplexing modes.

Currently let us focus on a 10MHz, FDD, Normal CP type downlink frame structure, with following configuration,